This is a follow-on from my recent Chemo & oligometastatic PCa post.
The idea of oligometastatic prostate cancer ("oligo" meaning "few") is that men with a few mets might be treated with radiation &/or surgery & perhaps survival will be extended. But does it make sense to use Taxotere, say, when one has only a few mets?
There were several responses to the post that cast doubt on the concept of oligometastatic disease. So I thought I'd discuss the background.
About 10 years ago, my new urologist (I had just relocated) reassured me that he could keep me alive - "unless you have mets - those guys don't do well." A black & white binary situation. The men who die with PCa rather than of it, were lucky enough to not have mets.
Much later, I asked him about oligometastatic disease, he said that if you have one met, you have a lot - "it's everywhere, you just can't see them."
But when a solitary met at L5 showed up on a bone scan, he put me in touch with a sympathetic radiation-oncologist. Normally, I would have been treated only if I was in pain. The doctor was surprised that I had no pain, & that there was no fracture. I remember thinking - why wait for pain/fracture? The answer, of course, is that it is pointless treating a solitary met if one believes that there must be a dozen or more unseen mets. Where would it stop? You can only have so much radiation.
The oligo topic raises a number of questions that have not really been answered:
1] Do oligometastases represent represent a subclass of PCa, in the same way that two-thirds of Gleason=3+3 cases never progress? Or do all oligo cases progess to many mets?
2] Given the state of PCa imaging technology, how can we be sure that a man has only 3 mets, say?
3] Regardless of whether a man truly has oligo-metastatic disease, is it worth treating him as though he has? e.g. would circulating tumor cells rule out oligo-therapy?
4] Does treatment extend life?
I'll tackle the first question.
...
Do fewer mets indicate less aggressive disease?
The CHAARTED study looked at chemo use up front [1]:
"... the combination of standard ADT and six cycles of docetaxel resulted in significantly longer overall survival than that with standard ADT alone in men with hormone-sensitive metastatic prostate cancer. The clinical benefit ... was more pronounced among patients with a higher burden of disease."
{"Prior studies of chemotherapy plus ADT, which did not show a benefit, were small studies that involved primarily patients with a relatively low tumor burden."}
"the median follow-up was 28.9 months"
It appears that a much longer follow-up would be required for low-volume disease. Why? It seems that low-volume men have better survival anyway.
A Johns Hopkins study [2] (2013) identified the "number of metastases (≤3 versus ≥4; HR 0.50 ...) as one of "four independently prognostic variables for {overall survival}".
A Belgium study [3] (2014) found that "a lower number of metastases at first presentation {was} associated with improved {prostate cancer-specific survival}."
(In this study, the men with only one met & a PSADT>3 months were still alive at 5 years.)
If men who present with oligo-mets have better survival, it looks as though they have a different type of metastatic PCa, that does not progress to multiple mets. If so, it might well be feasible to treat the mets individually.
Here is Dr. Myers:
askdrmyers.wordpress.com/20...
askdrmyers.wordpress.com/20...
-Patrick
[1] nejm.org/doi/full/10.1056/N...